Crashes (logout) on high sierra

Let me start by saying I've been using F.lux for years and I've enjoyed it very much.

I've updated my MBP 15 about 6 months ago to High Sierra, and it's been crashing once a day ever since.
Every time I close the lid and it goes to sleep, next time I open it - I'm in the login screen after a crash/logout (all apps are closed, etc).

The Console app showed crashes related to SkyLight.framework and WindowServer, I've decided to try and remove F.lux to see if it's the culprit.
It's been several days since the last crash.